[JoeF]

dhmartens, ,
Fun selects on those scale models! The viewing had me think: dhmartens may have solved the topic's deal: tote a scale model and do one of two things:

1. Actually hang glide the scale model and accept the super sink rate with real self pilot onboard.

2. Feed the scale model some unobtanium zap to grow the scale model to full size and have a great flight session. At the end of the session wipe the HG with shrinking moist and pack away the obtained scale model.

Nice go ...!
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In fiction, it is certainly possible to imagine a magical fluid or potion that could cause a scale model hang glider to grow into a full-sized hang glider. However, this would require suspending disbelief and accepting that such a fluid or potion exists within the rules of the fictional universe.

The exact details of how such a fluid or potion would work would depend on the specific rules and mechanics of the fictional universe. For example, the fluid could contain special growth agents that cause the materials of the scale model to rapidly expand and transform into a full-sized hang glider. Alternatively, the potion could contain magical energy that causes the materials of the scale model to transform into a full-sized hang glider through a more mystical process.

Ultimately, the mechanics of how the magic fluid or potion would work to transform the scale model hang glider into a full-sized hang glider would be up to the imagination of the author or creator of the fictional universe.

Maybe just get to the site with the toted scale model and shrink oneself and then pilot the deal. Finishing the session, expand self to normal again.

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Both 7075-T6 and 6061-T6 are popular aluminum alloys that are commonly used in aerospace and structural applications. However, they have slightly different mechanical properties that can affect their buckling behavior.

Assuming the 5 ft long, 2 inch outside diameter, and 1/32 inch wall thickness aluminum tube is perfectly straight and uniform, we can calculate the critical buckling load using the Euler buckling equation:

P = (π²EI)/(KL)

Where P is the critical buckling load, E is the modulus of elasticity, I is the area moment of inertia, K is the effective length factor, and L is the length of the column.

For both 7075-T6 and 6061-T6 aluminum tubes, we can calculate their respective critical buckling loads and compare them.

For 7075-T6 aluminum tube:

Modulus of elasticity (E) = 71.7 GPa
Area moment of inertia (I) = π/4 * (2 in)^4 - π/4 * (1.9375 in)^4 = 5.2 × 10^-4 m^4
Effective length factor (K) = 1 (assuming pinned-pinned boundary conditions)
Length (L) = 5 ft = 1.524 m
Plugging in these values into the Euler buckling equation, we get:

P = (π² * 71.7 GPa * 5.2 × 10^-4 m^4) / (1 * 1.524 m) = 34.3 kN

For 6061-T6 aluminum tube:

Modulus of elasticity (E) = 68.9 GPa
Area moment of inertia (I) = π/4 * (2 in)^4 - π/4 * (1.9375 in)^4 = 5.2 × 10^-4 m^4
Effective length factor (K) = 1 (assuming pinned-pinned boundary conditions)
Length (L) = 5 ft = 1.524 m
Plugging in these values into the Euler buckling equation, we get:

P = (π² * 68.9 GPa * 5.2 × 10^-4 m^4) / (1 * 1.524 m) = 33.0 kN

Comparing the critical buckling loads of the two aluminum tubes, we see that the 7075-T6 aluminum tube has a slightly higher critical buckling load than the 6061-T6 aluminum tube. This is due to the higher modulus of elasticity of 7075-T6 aluminum, which means it can withstand higher stresses before buckling. However, the difference in critical buckling load is relatively small, and both tubes should be able to withstand similar loads before buckling occurs. It is worth noting that these calculations assume ideal conditions and do not account for imperfections or variations in the material properties that can affect the buckling behavior of the aluminum tubes.

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Misc. notes toward thread's topic:
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How lines that cause compression in a beam attach to the end of the beam in compression can significantly affect the buckling behavior of the compressed beam.
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https://books.google.com/books?id=ljSn7 ... ns&f=false

[dhmartens]

From what I read Bautek is a successful German Hang gliding manufacturer that had series of shortpack gliders that they currently maintain but no longer sell new models as the used market provides enough supply.
https://forum.hanggliding.org/viewtopic.php?t=24201
Infomation from the link above states that the Bautek may have had telescopic leading edges but this cannot be verified.
Are there any videos or drawings or pdf vfiles that show how these glider are set up?

[JoeF]

dhmartens,
I've not found yet any verification of the "telescopic" spars of Bautek. Be ready for short intersleeving as compared to long telescopic insertions.
Their "short pack" is longer than the packs in high focus in this topic thread, but one may learn from anyone's effort to short pack, even if tiny pack is not achieved.
One online Bautek text quote: "you can easily short pack them so that they fit into every garage!" The "garage" invite is large compared to "tiny packing.
, I'd surmise." Bautek comments about the bowsprit Astir: "Transport and storage present no problem as the Astir has a short-pack length of 3.00 m (9.8 ft); it therefore fits inside most station wagons." That has a focus that is about twice the size of the tiny packing of this topic thread's maximum; some of us are even aiming for 1 m tiny packing or less; that would put the Astir at about 300% of a 1 m target for packing.
The "Packing the Airfex / Funfex / Perfex / Lightfex short to 1,90 m" video bespeaks and demonstrates 1.90 m "short" packing that resolves the needs of many pilots, but that is about 200% larger than the 1 m in focus for a faction of seekers related to the present topic thread. The Finsterwalder-Charly https://finsterwalder-charly.de/en/hang ... ories.html "short" packs are certainly with pleasant histories and stories of fliking (fly and hike).

SmallCarPassengerSide2mFexShortPack.jpg (39.71 KiB) Viewed 1110 times

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What might we learn from the 1.9 m for the shorter tiny-pack movement?
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Checklist?
Recording that says a step, pauses, says a step pauses,......
Numbered tags? March from tag #1 , #2, . . . to the end tag? Tags or markers on the parts.
Wing without ribs?
Nestable beams? Telescopic beams?
Longer bag zipper to reduce sliding of parts?
Mods for more conservative flying? Lighter sail?

[Chris McKeon]

OK, I want to address how being able to [Short Pack] Ones Glider. Also when I saw the Photos of those Two Guys having Their Short Packed Gliders on Their Backs. Seeing how that They could Pack their Gliders to a road. Being able to do this has been seen as an Potential very helpful way that I could Back-Pack My Own Glider..

QUESTION:

Is it that i am the only Pilot Who Flies XC, that see this as a potential Great Aid to a Pilot?


https://ushawks.org/forum/viewtopic.php ... 490#p33376

[JoeF]

Chris, you are not alone on the matter!

FunFex2mpacking.jpg (18.63 KiB) Viewed 1108 times

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[JoeF]

Some of the concepts and points in another topic are here upon called to help resolve, perhaps, tiny packing:
Here is the link to our forum's other topic to be studied for massaging the tiny-pack deal: https://ushawks.org/forum/viewtopic.php?f=2&t=2181

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Further: Though a long video, some people in the tiny-pack movement may enjoy the quality presentation in the following video concerning graphene, as the future of HG may well be deeply affected by graphene: Making Graphene could KILL you... but we did it anyway?!


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Beyond my $ level, but one may get a sense of state-of-the-art matters for graphene supply:
https://www.matexcel.com/category/products/graphene/
And I do not have any mastery over the offered graphene products.

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[JoeF]

For some HG experiments cased Mylar forming captive columns may be set on a taut mainsail and then overwrapped with a second sail to achieve various airfoils.

StuffersCasedSemiCirclesOverwrappedHnLanchoring001.jpg (40.49 KiB) Viewed 1068 times

[JoeF]

Re: prior post:
The semicircled cross-section of bent Mylar sheet may be form set at HG assembly by one of many methods. Those methods may be noted for selection. Other movement workers may provide methods not found mentioned below:

Full textile case that forces a limit of form.

String tie LE edge of Mylar to LE of HG. Then string tie rear edge of the Mylar sheet to the mainsail using strings perma-set into the mainsail, perhaps. Holes near the rear edge of the Mylar could be used to tie the Mylar sheet.

Have a large-mesh light net secured to the front edge of the Mylar sheet; tote such as such; then at assembly tie rear edge of that net to the rear edge of the Mylar sheet and thus forcing the captive semi-circle form of the Mylar sheet.

Have a set of string loops ready to be placed over castle towers notched into the edges of the Mylar sheet. The loops would have a length that would force the semi-circle form.

Have a set of holes near the edge of the Mylar sheet. Have a set of strings that have a rotatable T tip that locks naturally after inserting into the holes. The settled lengths of the strings forces the semicircle form of the Mylar sheet. "barbed strings" These barbed strings could be removed at packing. Alternatively, the set of strings could be permaset on one edge of the Mylar sheet while have the other end of the strings barbed for poking through the rear edge of the Mylar sheet (having a set of holes in the sheet) for a T anchoring as the barb rotates naturally. ChatGPT helps out here: "The strings you are referring to are commonly known as "barbed cords" or "barbed strings." They are also sometimes referred to as "locking cords," "barbed ties," or "security ties." These types of strings are often used in various industries for securing and fastening objects such as tags, labels, and bags. They typically have a plastic or metal barb at one end that is designed to lock securely into a hole or slot, holding the object in place."

A method that does not need hook-and-loop to secure the upper and lower semicircle Mylar forms to the leading edge of the HG wing: perma-string tie the front edges of the upper and lower Mylar sheets. When wrapping the overlap sail part one may find that the two string-joined semi-circular forms seat firmly to the LE of the wing. Still, the overwrapping sail may be secured to the taut mainsail using hook-and-loop aft of the LE a good distance.

[JoeF]

How might this affect tiny-packing of some HGs?
How to make big things out of small pieces
Researchers invent a new approach to assembling big structures — even airplanes and bridges — out of small interlocking composite components.
David L. Chandler, MIT News Office
Publication Date:August 15, 2013

[JoeF]

Soft-line rings?
as "rigging rings"

Have soft line form a ring, perhaps many turns of line to thicken the ring; cinch the two ends of the wrapping line to finish the ring of line.

Consider using a ring of line as a rigging part. The ring might hold points on a tiny-packed HG; e.g., a rigging ring might stay the following path: nose, kingpost point, aft keel point, queenpost point, and finishing at the start point of the nose: no tangs, only stops to stay positions in beam tips. Maybe have fewer HG parts results from using rigging rings! Just exampled was one rig ring instead of four segmented rig lines.

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